protected Joint(JointDef def) { Debug.Assert(def.bodyA != def.bodyB); _type = def.type; _bodyA = def.bodyA; _bodyB = def.bodyB; _collideConnected = def.collideConnected; _userData = def.userData; _edgeA = new JointEdge(); _edgeB = new JointEdge(); }
// This is used to prevent connected bodies from colliding. // It may lie, depending on the collideConnected flag. internal bool ShouldCollide(Body other) { // At least one body should be dynamic. if (_type != BodyType.Dynamic && other._type != BodyType.Dynamic) { return(false); } // Does a joint prevent collision? for (JointEdge jn = _jointList; jn != null; jn = jn.Next) { if (jn.Other == other) { if (jn.Joint._collideConnected == false) { return(false); } } } return(true); }
void Solve(ref TimeStep step) { // Size the island for the worst case. _island.Reset(_bodyCount, _contactManager._contactCount, _jointCount, _contactManager.ContactListener); // Clear all the island flags. for (Body b = _bodyList; b != null; b = b._next) { b._flags &= ~BodyFlags.Island; } for (Contact c = _contactManager._contactList; c != null; c = c._next) { c._flags &= ~ContactFlags.Island; } for (Joint j = _jointList; j != null; j = j._next) { j._islandFlag = false; } // Build and simulate all awake islands. int stackSize = _bodyCount; if (stackSize > stack.Length) { stack = new Body[Math.Max(stack.Length * 2, stackSize)]; } for (Body seed = _bodyList; seed != null; seed = seed._next) { if ((seed._flags & (BodyFlags.Island)) != BodyFlags.None) { continue; } if (seed.IsAwake() == false || seed.IsActive() == false) { continue; } // The seed can be dynamic or kinematic. if (seed.GetType() == BodyType.Static) { continue; } // Reset island and stack. _island.Clear(); int stackCount = 0; stack[stackCount++] = seed; seed._flags |= BodyFlags.Island; // Perform a depth first search (DFS) on the constraint graph. while (stackCount > 0) { // Grab the next body off the stack and add it to the island. Body b = stack[--stackCount]; Debug.Assert(b.IsActive() == true); _island.Add(b); // Make sure the body is awake. b.SetAwake(true); // To keep islands as small as possible, we don't // propagate islands across static bodies. if (b.GetType() == BodyType.Static) { continue; } // Search all contacts connected to this body. for (ContactEdge ce = b._contactList; ce != null; ce = ce.Next) { Contact contact = ce.Contact; // Has this contact already been added to an island? if ((contact._flags & ContactFlags.Island) != ContactFlags.None) { continue; } // Is this contact solid and touching? if (!ce.Contact.IsEnabled() || !ce.Contact.IsTouching()) { continue; } // Skip sensors. bool sensorA = contact._fixtureA._isSensor; bool sensorB = contact._fixtureB._isSensor; if (sensorA || sensorB) { continue; } _island.Add(contact); contact._flags |= ContactFlags.Island; Body other = ce.Other; // Was the other body already added to this island? if ((other._flags & BodyFlags.Island) != BodyFlags.None) { continue; } Debug.Assert(stackCount < stackSize); stack[stackCount++] = other; other._flags |= BodyFlags.Island; } // Search all joints connect to this body. for (JointEdge je = b._jointList; je != null; je = je.Next) { if (je.Joint._islandFlag == true) { continue; } Body other = je.Other; // Don't simulate joints connected to inactive bodies. if (other.IsActive() == false) { continue; } _island.Add(je.Joint); je.Joint._islandFlag = true; if ((other._flags & BodyFlags.Island) != BodyFlags.None) { continue; } Debug.Assert(stackCount < stackSize); stack[stackCount++] = other; other._flags |= BodyFlags.Island; } } _island.Solve(ref step, Gravity, _allowSleep); // Post solve cleanup. for (int i = 0; i < _island._bodyCount; ++i) { // Allow static bodies to participate in other islands. Body b = _island._bodies[i]; if (b.GetType() == BodyType.Static) { b._flags &= ~BodyFlags.Island; } } } // Synchronize fixtures, check for out of range bodies. for (Body b = _bodyList; b != null; b = b.GetNext()) { if (!b.IsAwake() || !b.IsActive()) { continue; } if (b.GetType() == BodyType.Static) { continue; } // Update fixtures (for broad-phase). b.SynchronizeFixtures(); } // Look for new contacts. _contactManager.FindNewContacts(); }
/// Destroy a rigid body given a definition. No reference to the definition /// is retained. This function is locked during callbacks. /// @warning This automatically deletes all associated shapes and joints. /// @warning This function is locked during callbacks. public void DestroyBody(Body b) { Debug.Assert(_bodyCount > 0); Debug.Assert(!IsLocked); if (IsLocked) { return; } // Delete the attached joints. JointEdge je = b._jointList; while (je != null) { JointEdge je0 = je; je = je.Next; if (DestructionListener != null) { DestructionListener.SayGoodbye(je0.Joint); } DestroyJoint(je0.Joint); } b._jointList = null; // Delete the attached contacts. ContactEdge ce = b._contactList; while (ce != null) { ContactEdge ce0 = ce; ce = ce.Next; _contactManager.Destroy(ce0.Contact); } b._contactList = null; // Delete the attached fixtures. This destroys broad-phase proxies. Fixture f = b._fixtureList; while (f != null) { Fixture f0 = f; f = f._next; if (DestructionListener != null) { DestructionListener.SayGoodbye(f0); } f0.DestroyProxy(_contactManager._broadPhase); f0.Destroy(); } b._fixtureList = null; b._fixtureCount = 0; // Remove world body list. if (b._prev != null) { b._prev._next = b._next; } if (b._next != null) { b._next._prev = b._prev; } if (b == _bodyList) { _bodyList = b._next; } --_bodyCount; }
private static Joint GetFirstGearableJoint(JointEdge je) { while (je != null && !(je.Joint is PrismaticJoint || je.Joint is RevoluteJoint)) { je = je.Next; } if (je == null) { throw (new Exception("missing gear joint target")); } return je.Joint; }